High linear power amplifier for multicarrier satellite communications

Paper i proceeding, 2014

High linearity performance in transmitters is receiving continuously attention due to demands of higher data rates in satellite communication links. This paper presents a GaAs pHEMT MMIC high linear power amplifier intended for multicarrier operation at C-band. Junction temperature prediction methods are considered during the amplifier design to keep the temperature under control and achieve high reliability required for space applications. The design method is focused in high linearity optimizing the loads and using a non-linear transistor model to predict harmonic generation and intermodulation products. The amplifier was characterized in terms of S-parameters, single tone output power and two tone output power.

The measured S-parameters shows a flattened gain over 25 dB between 3 and 6 GHz. The 1dB compression point is measured at 26.7 dBm and the output third order intercept point (OIP3) is above 40 dBm in the band reaching a maximum of 41.7 dBm at 4.5 GHz. The power consumption is lower than 2.5 W and the junction temperatures are calculated under 105 °C.